Method and apparatus for evaluating offshore pipeline laying operations

ABSTRACT

Methods and apparatus for conducting evaluations of offshore pipe-line laying operations and characterized by the performance of inspection operations, in relation to submerged pipeline means, prior to the termination of a pipeline laying operation. The inspection operation is performed while a floating vessel means, effecting the pipeline laying operation, remains operable to lay and/or retrieve pipeline increment means containing a defect detected during the inspection operation.

United States Patent Jones June 19, 1973 [54] METHOD AND APPARATUS FOR2,459,499 1/1949 Caste] 73/151 X EVALUATING OFFSHORE PIPELINE 3,562,9162/1971 Duckworth 73/151 LAYING OPERATIONS Primary Examiner-Jacob ShapiroAttorney-Burns, Doane, Swecker & Mathis [57] ABSTRACT Methods andapparatus for conducting evaluations of offshore pipe-line layingoperations and characterized by the performance of inspectionoperations, in relation to submerged pipeline means, prior to thetermination of a pipeline laying operation. The inspection operation isperformed while a floating vessel means, effecting the pipeline layingoperation, remains operable to lay and/or retrieve pipeline incrementmeans containing a defect detected during the inspection operation.

22 Claims, 16 Drawing Figures [75] Inventor: Raymond E. Jones, Houston,Tex.

[73] Assignee: Brown & Root, Inc., Houston, Tex.

[22] Filed: May 28, 1971 211 App]. No.: 147,834

[52] US. Cl. 61/723, 73/151 [51] Int. Cl. F161 1/00 [58] Field of Search61/723, 72.1, 72.4;

[56] References Cited UNITED STATES PATENTS 3,438,213 4/1969 Broussardet a1.

1,805,343 5/1931 Robbins 73/151 X PAIENIEL 3.739.591

SHEET 1 0i 6 INVENTOR 4. 1 a U I RAYMOND E. JONES ,1? BY e zw 54,014, m

ATTORNEYS PAIENTEDJUNISIHH 739,5391

SHEET 2 0f 6 FIG. 20

PATENTED JUN 1 sum SHEEY 3 0F 6 PAIENIED JUN 1 9 ms SHEET '& 0f 6 rU IPATENIED JUN 1 91915 SHEU S [If 6 PAIENTEU JUN v 9 ma SHEET 6 0F 6METHOD AND APPARATUS FOR EVALUATING OFFSHORE PIPELINE LAYING OPERATIONSOffshore pipeline laying operations are complex and costly in nature.

Contributing to the cost and complications entailed in offshorepipelaying operations are the inspections which must necessarily beperformed to ensure that a pipeline, when laid, is in structurallysound, safe, useable form.

Such inspection operations are concerned with detecting adverseconditions which would impair the safety or operating efficiency of thelaid pipeline, or confirming a satisfactory condition.

One common fault sought to be detected involves a buckle condition whichmight inadvertently result from stresses imposed upon a pipeline duringa laying operation. Such stresses would be imposed on the pipeline as itwas being manipulated from a pipelaying barge, or other floating vesselmeans, downwardly through a body of water into a position supported on asubmerged surface.

Traditionally, such inspection operations have been performed after thepipeline laying operation has been completed. Where a buckle conditionhas been detected utilizing this conventional inspection technique, ithas generally been necessary to resort to expensive means for raisingthe buckled pipeline portion to the surface and effect repairs.

At times, when it has not been feasible to raise a pipeline portioncontaining a buckle, it has been necessary to go to the extreme measureof either cutting out a buckled portion and effecting underwater repairsor raising to the surface the entire portion of the pipeline extendingfrom the buckle area to a free end or terminus of the pipeline.

Such repair operations can be extremely costly and entail severalhundred thousand dollars in costs. In addition, such repair operationssignificantly delay the placing of a pipeline in operating condition.

Bearing such contingencies in mind, it is a principal object of thepresent invention to provide a pipeline inspection or conditiondetecting operation which enables abnormalities to be detected prior tothe termination of a pipeline laying operation.

It is a particular object of the invention to provide such techniques bymeans of which inspection or condition detecting operations may beperformed generally throughout the pipeline laying operation so as toprovide prompt indications of undesirable or abnormal prior conditions,or confirm a satisfactory condition.

It is a further object of the invention to provide such techniques whichenable abnormalities or defects to be detected before underwatercurrents or tides have induced partial or complete burying of pipelines,which burying might significantly impair repair operations.

It is likewise an object of the invention to provide such techniqueswhich enable inspection or condition detection operations to beperformed while a pipeline laying barge, or other floating vessel meanseffecting pipe-laying, remains operable to retrieve previously laidpipeline increment means containing a detected adverse condition.

In relation to a preferred embodiment of the invention, it is an objectto provide a pipeline condition detecting arrangement which enables adetecting means to be propelled to a location within a submergedpipeline section, and then be disconnected from an extraneous powersource which effected the propelling operation. This disconnectingsimplifies the subsequent detecting operation and enables it to beperformed without reliance upon power sources carried by the detectingunit.

A still further object of the invention, in relation to I the preferredembodiment, is to enable scanning ma- However, it has been found thatthe objectives heretofore set forth may be implemented, at least inpart, by practicing the following method aspects of the invention.

One such method aspect involves the performing of inspection or pipelinecondition detecting operations, in relation to a submerged pipelineportion, while a portion of the pipeline remains supported on floatingvessel means such that the submerged pipeline portion being inspectedmay be readily retrieved using laying apparatus and techniques.

Another independent aspect of the invention relates to a method ofdetecting a submerged pipeline condition where a pipeline is supportedat an offshore location with a first portion supported on a submergedsurface. In this technique, a second portion is supported on floatingvessel means and a third portion extends through a body of water betweenthe first and second pipeline portions.

In this second method aspect, a pipeline condition detecting means ispositioned within the interior of a submerged portion of the pipeline.Utilizing this detecting means, a condition of the submerged pipelineportion is detected while the pipeline remains supported by the floatingvessel means. In addition, the floating vessel means remains operable toretrieve the submerged pipeline portion by exerting a retrieving forceon the second pipeline portion.

This technique is particularly advantageously em ployed in a third,independently significant method aspect of the invention. In this thirdmethod aspect of the invention the detecting means is caused to undergorelative movement in relation to relatively newly laid increment meansof submerged pipeline means resting on a submerged surface so as toindicate dimensional irregularities such as buckles, etc.

In afourth, independently significant, aspect of the invention thepipeline indicating means is propelled from the floating vessel means toits detecting location within the first pipeline portion. In this fourthmethod aspect ofthe invention, scanning movement of the pipelinecondition detecting means is effected by connecting the pipelinecondition detecting means with conventional pipeline section alignmentmeans (i.e. a line up clamp) on the floating vessel means. With thisarrangement, normal repositioning of the pipeline section alignmentmeans as it is moved into alignment with a new pipeline joint willinduce relative movement of the pipeline condition detecting means andrelatively recently laid additional increment means of the pipelinelaying on a submerged surface. This movement will cause the detectingmeans to scan the newly laid increment means for irregularities.

A fifth facet of the invention, significant itself, relates to apropulsion technique for operating the detecting means. This propulsiontechnique entails the utilization of pressurized air to concurrently (l)latch the detecting means in coupled engagement with a source ofpressurized air, (2) extend drive means into engagement with theinterior of a pipeline, and (3) actuate the drive means for propulsionpurposes. Reduction of the pressure of the pressurized gas will serve toconcurrently (l) uncouple the source of pressurized air from thedetecting means, (2) retract or permit retraction of the drive meansfrom effective driving engagement with the pipeline interior, and (3)dea'ctuate the drive means itself.

A sixth independently significant aspect of the invention entails theretrieval of a pipeline increment, con-- taining an irregularity, byoperation of pipeline tensioning means used for normal layingoperations. This retrieval operation may serve to concurrently retrievethe detecting means itself so as to enable it to be rendered operationalfor subsequent detecting operations after the impaired section has beenreplaced or reconditioned.

A seventh independently significant method aspect of the inventionentails the actual retrieval of a pipeline increment containing a bucklecondition or other irregularity, by merely reversing the normaltechnique employed in the laying operation and retrieving this incrementon board the floating vessel used for pipeline laying operations.

In conjunction with these independently significant method aspects ofthe invention, which are mutually compatible so as to provide cumulativebenefits, the invention also contemplates various combinations ofapparatus elements which uniquely interact to provide the advantageousfunctions heretofore described.

In describing the invention, reference will be made to preferredembodiments by way of example. However, it will be recognized that thepreferred example is not limiting with respect to the scope of theinvention insofar as detecting apparatus is concerned, pipelaying orretrieving apparatus is concerned, or the condition being detected isconcerned.

Bearing this in mind, the invention will now be described with referenceto certain illustrations.

DRAWINGS 1 Preferred embodiments of the invention are set forth in theappended drawings.

In the drawings:

FIG. 1a schematically depicts an offshore pipeline laying operation atthe point in time where laying has been initiated and a pipelinecondition detecting means is positioned on the laying vessel. Thisdetecting means is disposed for subsequent propulsion to a locationdisposed within a submerged pipeline portion resting-on a submergedsurface;

FIG. 1b schematically illustrates the FIG. 1a assembly with the pipelinecondition detecting means disposed within the interior of an incrementof a submerged portion of a pipeline which is generally resting on orlocated adjacent a submerged surface;

FIG. llc schematically depicts the FIG. Ia assembly with the pipelinecondition detecting means disposed, as described in connection with FIG.1b, and operable to scan the interior of the submerged pipelineincrement in order to detect pipeline irregularities. An upper portionof the pipeline supported on the floating vessel means so as to permitretrieval of the submerged pipeline increment being scanned. FIG. 1calso schematically illustrates the interconnection of the pipelinedetecting means with a conventional line up clamp or pipeline alignmentmeans which is used to longitudinally align a new pipeline joint withthe body of the pipeline for welding or interconnecting purposes;

FIGS. 2a-2d provide enlarged, schematic views of operational facilitieslocated on the floating vessel means shown in FIGS. la-lc, it beingunderstood that for purposes of ease and clarity of illustration, notall of the components shown in FIGS. 2a-2d are depicted in the schematicviews of FIGS. la-lc;

FIG. 2a illustrates components as they would be arranged during aninitial welding operation, with the line up clamp or pipeline alignmentmeans securing a recently added pipeline section or joint inlongitudinal alignment with previously welded or assembled joints forwelding purposes. FIG. 2a further schematically depicts the manner inwhich the previously welded pipeline body is engaged by pipelinetensioning means which may be employed for pipeline laying or retrievingpurposes, as in the manner generally described in Lawrence U.S. Pat. No.3,390,532 and Lawrence U.S. Pat. No. 3,487,648. In FIG. 2a the pipelinesection alignment means is disposed in connected relation with aflexible draft device such as a cable, rope, or chain, which extendsfrom the pipeline section alignment means through the pipeline interiorto the pipeline condition detecting means described in connection withFIGS. la-lc;

FIG. 2b schematically depicts the FIG. 2a components after the weldingof the new joint (which may comprise the welding of an initial beadstring or other partial or even complete welding), with the new sectionhaving been advanced relative to the pipeline vessel toward thesubmerged surface (normally effected by movement of the pipeline vesselaway from the previously laid pipeline portion);

FIG. 2c depicts the FIG. 2b components with a second new pipeline jointdisposed in position to be longitudinally welded or otherwise coupled tothe remaining pipeline;

FIG. 2d illustrates the second additional pipeline increment or jointdisposed in longitudinal, contiguous alignment with the previouslywelded pipeline body, with the line up clamp or pipeline sectionalignment means being moved away from the previously laid pipeline so asto bring it into alignment securing cooperation with the junctionbetween the second additional joint and the previously welded joint.FIG. 2d further illustrates the movement of the pipeline sectionalignment means which induces scanning or condition detecting movementof the pipeline condition detecting means described in connection withFIGS. la-lc;

FIG. 3 provides an enlarged, longitudinally extending, sectional view ofthe submerged portion of the pipeline shown in FIG. 10 containing theaforesaid pipeline condition detecting means, this pipeline conditiondetecting means being shown in side elevation within the interior of thelongitudinally sectioned pipeline;

FIG. 4 provides a transverse sectional view of the FIG. 3 assembly, andpresents an end elevationalview of a pressurized air operated latchingmechanism which serves to detachably secure a source of pressurized air,i.e. a flexible air hose, to a power train assembly of the pipelinecondition detecting means, FIG. 4 being viewed along section line 44 asshown in FIG. 3;

FIG. 5 provides a transverse sectional view of the FIG. 3 assembly, asviewed along section line 55 of FIG. 3, and illustrates resilientlybiased centering wheels incorporated at the left end of the pipelinecondition detecting means, as shown in FIG. 3, and further illustratespneumatic connections extending to the latching mechanism shown in FIG.4;

FIG. 6 provides a transverse sectional view of the FIG. 3 assembly,viewing the interior of the right end of the pipeline detecting means asshown by reference to section line 6-6 of FIG. 3, and depicts structuralaspects of propelling components including pneumatic motor actuateddrive wheels and mechanisms for selectively extending or retractingthese drive wheels (i.e. for exerting or releasing radially outwardlydirected biasing force exerted upon the biasing means);

FIG. 7 provides a transverse sectional view of the FIG. 3 assembly, asviewed along section line 77 of FIG. 3, and illustrates in endelevation, pneumatically biased centering wheels disposed at the rightend of the pipeline condition detecting means shown in FIG. 3;

FIG. 8 provides an enlarged, transverse sectional view of one of threedrive wheel components shown in FIG. 6, as viewed along section line 8-8of FIG. 6;

FIG. 9 provides an enlarged, transverse sectional view of a motorsupport and reaction surface portion of one of the three driveassemblies shown in FIG. 6, as viewed along section'line 9-9 of FIG. 6;

FIG. 10 provides a partially sectioned and enlarged view of thepreviously noted latching mechanism, with components generally disposedas shown in FIG.'3; and

FIG. 11 provides an enlarged, partially sectioned, side elevational viewof one representative centering wheel shown in elevation in each ofFIGS. 5 and 7.

DESCRIPTION OF PREFERRED EMBODIMENT Overall Context of Invention PipeLaying Vessel FIGS. 1a and 2a illustrate the overall context withinwhich the preferred embodiment of the invention is practiced.

As shown in these Figures, a pipeline laying installation 1 includes afloating vessel means 2. Floating vessel means 2 may comprise apipe-laying barge of the type now used in major offshore pipeline layingoperations, or for that matter any vessel operable to effect pipelayingoperations.

Laying barge 2 may be provided with a pipeline tensioning means 3 of thewheel or caterpillar type and generally corresponding in mode ofoperation to the arrangement featured in Lawrence U.S. Pat. No.3,390,532.

Floating vessel means 2 may also include a buoyant ramp or "stinger" 4pivotally supported at connection joint 5 to one barge end.

Connecting joint 5 may correspond to the hitch structure featured inLawrence U.S. Pat. No.

3,390,532. The buoyant ramp or stinger 4 may correspond generally tostructures of the type featured in Lawrence U.S. Pat. No. 3,390,532,Hauber U.S. Pat. No. 3,280,571, and/or Rochelle et al. U.S. Pat. No.3,507,126. A series of pipe cradling, roller assemblies 6 may beprovided on the barge 2 as well as on the stinger 4, in the mannergenerally described in Lawrence U.S. Pat. No. 3,390,532, so as toprovide longitudinal support underlying pipeline portions.

Such roller or cradle assemblies 6 serve to slidably support a pipeline7 being laid by the barge 2. While a series of such roller assemblies 6may be provided to provide a plurality of pipeline supports spacedlongitudinally along the pipeline, only one such support 6 isschematically shown in FIG. la.

Welding In many instances, it is contemplated that the invention may bepracticed in the context of a conventional welding-type, pipe joiningoperation. In such an operation, one, or a series, of welding stations,may be disposed longitudinally along the pipeline portion supported onthe barge 2. At each such welding station, when the pipeline issubstantially immobilized (except possibly for wave action inducedmovement) relative to the barge 2, welding is effected at a pipelinejoint located at the station. Where multiple stations are in volved,each joint junction will be partially welded at each of several weldingstations, with the total welding provided by the several weld stationsproducing a completed weld joint.

One such representative weld station 8 is shown in FIG. 2a. Weld station8 may comprise an automatic welding unit or a conventional stationoperated by manual welders.

Solely by way of example, the welding station 8 shown in FIG. 2a isshown as the first welding station which would provide the initial orbead" weld between a new joint and the previously welded pipeline body,in the event that a multiple welding station system was being employed.It is also possible-that station 8 could comprise an automatic weldingstation where complete welding of the joint would be completed.

Where multiple stations would be employed, several additional stations 8ordinarily would be interposed between the station 8, shown in FIG. 2a,and the tensioning unit 3.

As shown in FIG. 2a, initial installation of a new pipeline joint orincrement 9 may be facilitated by a line up clamp or pipeline alignmentmeans 10. Such a pipeline alignment means 10 would serve to secure thejoint 9 in longitudinal and generally contiguous alignment with thepreviously welded pipeline body 7.

Conventionally, pipeline alignment means 10, now well known in the art,may comprise a body 11 supporting radially movable extendable andcontractible pipeline alignment clamps. Such alignment clamps may beselectively motivated by pressurized air conveyed to them by an air pipe(i.e. conduit or hose) [2. Air pipe 12, as shown in FIG. 2a, will extendlongitudinally of line up clamp 10. When disposed in alignment position,alignment means 10 will be disposed at the junction 13 between pipelinebody 7 and new pipeline joint 9 and air pipe 12 will extend through thenew joint 9. A flexible branch air line 14 may be detachably connectedwith air pipe 12 and serve to supply air to pipe 12 for transmittal tomechanism 10 under the manually controlled influence of valve located inpipe 12.

In operation of this mechanism, with the clamp positioned generally asshown in FIG. 2a, pressurized air would be supplied to pipe 12 so as toactivate and radially extend the line up clamps of mechanism 10. Thisextension of line up clamp elements would serve to interlock or securejoint 9 in longitudinally aligned and contiguous relation with pipelinebody 7. The aligning and securing operation of the clamps may bemaintained by continuing to supply air to mechanism 10 with valve 15open or by closing the valve 15 so as to provide an entrapped body ofclamp-actuating pressurized air in the pipe 12 and mechanism 10.

When the securing operation at station 8 has been completed, the airpressure in pipe 12 may be reduced or vented so as to allow radiallyinwardly directed retraction of the line up clamp elements and thuspermit relocation of the mechanism 10 for welding operations relating toa second new joint.

During each securing operation, the tensioning means 3 will tend tomaintain the pipeline 7 generally stabilized in relation to the pipelinelaying vessel 2, while accommodating limited movement induced by waveaction as in the manner contemplated in Lawrence U.S. Pat. No. 3,390,532and Lawrence U.S. Pat. No. 3,487,648.

When welding has been completed, the pipeline vessel 2 will be moved tothe left, as shown in FIG. la so as, in essence, to cause the new. joint9 to move relative to vessel 2 toward the previously laid pipelineportion.

This stop and go operation will be continued until pipeline laying iscompleted.

PIPELINE PROFILE As shown in FIG. la, the pipeline laying operationthere depicted entails the laying of the pipeline 7 in a body of water15. Conventional techniques may be employed to both initiate andterminate the pipeline laying operations depicted in FIGS. 1a through1c.

The pipeline 7 comprises a first portion 7a lying on a submerged surface16. Portion 7a, in general, will be substantially completely supportedby the submerged surface 16 such that it is no longer subject to buckleinducing tendencies engendered during the pipeline laying operation.

A second pipeline portion 7b will be supported by the tensioning means 3and roller assemblies 6 of the floating vessel means 2.

A third pipeline portion 70 extends through water body 15 between thesecond pipeline portion 7b and the first pipeline portion 7a.

In general, pipeline portion 7c may be viewed as the portion extendingfrom the water surface 17 down to the general location of a tangency"point 18 where the pipeline moves into substantially full supportedenoperation, as water depths vary and as the elevation or configurationof the submerged surface 16 varies, the

pipeline zone 7c may undergo changes in shape, profile and/or dimension.In addition, as pipeline laying progresses, the length of portion 7awill continuously increase, with the configuration of portion 7adepending upon the pipelaying route and the configuration of thesubmerged surface 16 upon which it is resting.

By way of reference, this general mode of pipelaying is described inLawrence U.S. Pat. No. 3,390,532.

However, as will be appreciated, in view of the preceding and subsequentdiscussions relating to the inventive contribution herein presented, theinvention may be practiced in the context of a variety of pipelinelaying techniques including those described in Lawrence U.S. Pat. No.3,487,648, Rochelle et al. U.S. Pat. No. 3,507,126, Lawrence U.S. Pat.No. 3,472,034, and other patents and publications.

The general setting of the invention having been discussed, it nowbecomes appropriate to consider structural details of a pipelinecondition detecting means which may be employed in the practice of theinvention.

Pipeline Condition Detecting Means FIG. 10 schematically illustrates apipeline condition detecting means 19 disposed within the interior ofpipeline portion 7a.

Pipeline condition detecting means 19 is connected with a flexible draftdevice 20 such as a rope, cable, or

chain which extends from the detecting device 19 upwardly through theinterior of the pipeline body 7.

The manner in which draft device 20 is manipulated to induce relativemovement of detecting device 19 in relation to relatively newly added oradditional increments of pipeline portion will be subsequentlydescribed.

Suffice it to say, for the time being, that this relative movement willpermit scanning of such additional increments of pipeline portion 7avery shortly after such increments have been laid on the submergedsurface 16. This will permit an operator to determine at the earliestpossible moment, or at least prior to the termination of the pipelinelaying operation, the condition of the pipeline as it comes to rest onthe submerged surface 16.

The condition being detected may be any of several conditions normallyconsidered during pipeline laying operations.

Desirably, of course, the condition detected will involve a statusdevoid of unacceptable imperfections.

However, the detecting operation will be designed to locate unacceptableconditions such as pipeline buckles. Such buckle conditions wouldinvolve a distortion in pipeline cross section dimensions, resultingfrom a conduit buckling which would occur as pipeline joints move fromthe barge 2 through zone 7c to the submerged surface 16.

Although the present discussion will be confined to the detection of abuckle condition, it will be recognized that other adverse conditionsmay be detected including cracks, faulty joints, etc.

While a mechanical type of detecting unit will be subsequentlydescribed, other detecting devices might be employed, including those ofan optical or television nature, and including those which rely uponradiological, x-ray, sonic, or other radiated energy type testingoperations.

While it thus is apparent that the pipeline condition detectingoperation embraces a wide range of conditions and detection apparatus,it will be appreciated that the invention is primarily concerned withthe location of a condition which is detectable prior to the terminationof the laying of the pipeline but which will remain in the laid pipelineafter the termination of the laying operation unless detected andcorrected.

Thus, the invention is to be distinguished from operations relating todeterminationsof transient conditions which persist only during thelaying of the pipeline such as tension in the pipeline, orientation ofthe profile of the pipeline portion 7c, etc.

Bearing the general scope of the detecting operation in mind, structuraldetails of a detecting mechanism operable to detect a buckle conditionwill now be discussed.

Specific Structure of Buckle Detector Structural details of buckledetector 19 are illustrated in FIGS. 3-11.

Referring now to FIG. 3, it will be seen that buckle detector 19comprises a pair of mutually spaced, circular discs 21 and 22. Discs 21and 22 are interconnected by longitudinally extending andcircumferentially spaced framing members 23. Detector 19 is connectedwith draft means 20 by wayof a yoke 20a as shown in FIG. 3.

At least the foreward disc 21 will have a diameter such as to enable itto move freely through an unbuckled pipeline interior but be preventedfrom moving through the interior of a pipeline which has been subjectedto excessive buckling or cross-sectional distortion. Thus, at least disc21 will function as a buckle detecting device.

Detector unit 19 includes, among its basic components, an air conduit ormanifold 24 and an air operated latching mechanism 25 which serves todetachably connect the air conduit 24 to a flexible air hose 26.

Flexible air hose 26, when utilized, will extend from the mechanism 19through the interior of pipeline 7. As shown in FIGS. 1a and 1c, hose 26may extend to a reel or hose assembly 27, which-reel or hose assembly isprovided with means for connecting hose 26, in a conventional manner,with a compressor or other source of pressurized air. As will berecognized, the term pressurized air is herein used in a generic senseto include any pressurized gas or fluid.

Mechanism 19 is also provided with a plurality of centering wheels 28.

As shown in FIG. 5, three such centering wheels 28 are carried in asymmetrical, radially oriented pattern by buckle detecting plate 21.Similarly, three other centering wheel assemblies 28 are carried in asymmetrical and radially oriented arrangement by disc 22 in the mannergenerally depicted in FIG. 7.

In order to optimize the centering action of the wheel assemblies 28,the wheel patterns may be circumferentially displaced 180 in the mannergenerally depicted in FIGS. and'7.

A compressed air operated, propulsion system 29 included in buckledetector 19 may comprise a series of three radially oriented andsymmetrically arranged drive wheel assemblies 30, each arranged forradially gage a flange face 32 carried by flexible air conduit 26.

The propelling mechanism 29 serves to propel the detector 19 from thevessel 2 to the pipeline portion 7a. After this propulsion is effected,subsequent scanning movement of the detector 19 relative to the pipelineis effected by the draft means 20.

Prior to considering the manner in which detector 19 is propelled intooperative position and utilized to detect a pipeline condition, it willbe appropriate to consider specific structural and operationalcharacteristics of the latching mechanism 25, the drive wheel assemblies30 and the centering wheels 28.

LATCI-IING MECHANISM Structural details of the latching mechanism 25 areshown in FIGS. 3, 4, and 10.

As there shown, air conduit 24 of detector 19 is provided with a flangeface 31. Flange face 31 is operable to matingly and generally sealinglyand abuttingly en- The latch mechanism 25 which serves to secure theflange faces 31 and 32 in generally mutually abutting and sealedcooperation during the propulsion of detector 19, comprises a pluralityof pivoted latch means 33.

As shown in FIGS. 3 and 4, two such latch means are provided eachcomprising a body 34 connected to plate 21 by a pivot mount 35. Apneumatically operated piston and cylinder-type actuator 36 is alsoconnected to plate 21 in association with each latch body 34. Air foractuating the piston component 37 of each assembly 36 is derived from abranch conduit 38 extending from the primary air tube or conduit 24 ofthe detector 19. As

outwardly directed biasing extension and radially inshown in FIGS. 3 and4, the piston portion 37 includes a rod disposed in biasing cooperationwith an edge of the latching plate body 35.

Thus, when the flanges 31 and 32 are manually brought into abuttingcooperation, and pressurized air.

is supplied byconduit 26 to conduit or manifold 24, this air will betransmitted through conduit means 38 to piston and cylinder assemblies36. This air will actuate the assemblies 36 so as to cause the pistonrod components to bias plates 34 to the positions shown in FIGS. 3 and10. In these positions, the plate bodies 34 serve to press the flange 32axially against the flange 31 and thus detachably interlock the airsource 26 with the detector 19.

When the pressure of air in conduit 26 is released, biasing influence ofassembly means 36 is obviated. With this biasing influence thusobviated, the conduit means 26 may be pulled free of the assembly 19.

If desired, the latch body elements 34 may be biased to a limited extentinto the latching position shown in FIG. 3 by torsion springs or otherspring means. However, while such spring means would facilitate theinitial connecting of the conduit means 26 with the detector 19, thisbiasing would not be sufficient in and of itself to prevent thedetachment of air hose 26 from the detector 19 in response to theexertion of a pulling force on conduit means 26.

Whatever arrangement is employed, it is contemplated that when the airin conduit 26 is reduced in pressure, as by venting to the atmosphere,or by otherwise eflecting a substantial pressure reduction, the conduit26 will be retrievable to the deck of vessel 2 by the exertion of apulling force on the conduit 26. However, this pulling force will notinduce any significant longitudinal displacement of the detector 19relative to the pipeline interior.

llll

As will also be recognized, the actuating assemblies 36 may also be ofthe type which are spring biased to a retracted condition such that whenair pressure is reduced within these assemblies the pistons willautomatically retract so as to automatically cause the plates or latches34 to pivot outwardly and automatically free the flange 32 foruncoupling purposes.

DRIVE WHEEL ASSEMBLIES Structural details of the drive wheel means aregenerally depicted in FIGS. 3, 6, 8 and 9.

As shown in these Figures, each such drive wheel assembly 30 comprises abase plate 39 mounted for radially outwardly or inwardly directedmovement by means of rail means 40 and 41 which are secured to disc 22.A drive wheel 42 is journalled in bracket means 43 and 44 by bearingassemblies 45 and 46 as generally depicted in FIG. 8. Bracket means 43and 44 are connected with base plate 39, as shown in FIG. 8.

Each drive wheel 42 is connected with a drive shaft 47 which in turn isconnected, by a worm gear type transmission 48, with a pneumaticallyactuated drive motor 49. Each drive motor 49, as shown in FIG. 6, issupported by bracket means 50, which bracket means is carried by baseplate 39. As shown in FIG. 9, motor 49 provides a drive shaft 51 whichserves to motivate or rotate the worm gear element 52 in thetransmission mechanism 48.

Each pneumatic drive motor 49, which is of a rotary character, ismotivated by and connected with a source of pressurized air. This sourceof pressurized air as shown in FIGS. 3 and 6, may comprise a flexiblebranch conduit 53 extending from main air conduit or manifold 24.

With slide 39 biased radially outwardly, its associated drive wheel 42will be disposed in frictional engagement with the interior of apipeline, in the manner generally shown in FIG. 3. This will permitrotation of the drive wheel 42, as induced by operation of the motor 49,to induce longitudinal movement or propulsion of the detector assembly19 relative to the pipeline 29 so as to cause the detector 19 to bepropelled sequentially through the pipeline segments 7b and 70 to anoperable location within the interior of pipeline portion 7a, or otherportion.

When the outwardly directing biasing force is removed from plate 39,sufficient inward movement of plate 39 will occur as to permit the wheel42 to be effectively disengaged from driving cooperation with theinterior of the pipeline. Such disengagement may entail physicalseparation of the wheel from the pipeline interior or merely sufficientmovement to remove excessive frictional interaction between the drivewheel 42 and the pipeline interior.

Radially directed extension or contraction of the plate 39, operable tomanipulate the drive wheel 42 into and out of driving cooperation withthe pipeline interior, may be effected by a plate-movement controllingmotor means such as a reciprocable piston and cylinder assembly 54associated with each unit 30.

Each such assembly 54 may comprise a pneumatically actuated piston andcylinder assembly 54, the operation of which is effected by pressurizedair supplied by a branch conduit 55. As shown in FIG. 6, each suchbranch conduit 55 may be connected with and extend from the manifold ormain air conduit 24 of the detector 19.

A piston rod portion 56 of each assembly 54 is disposed for radiallydirected reciprocation and is arranged in abutable or engagedcooperation with the bracket 50.

Thus, when piston rod 56 is extended radially outwardly, the rod 56 willabuttingly engage the bracket 50 and cause the plate 39 to moveoutwardly so as to bias the wheel 42 into driving cooperation with thepipeline interior.

When the air pressure in mechanism 54 is reduced or vented to atmospherethrough the reduction of pressure in conduit 26, the biasing influenceof piston rod 56 will be removed.

With the outwardly directed biasing influence of piston rod 56 removed,the plate 39 will be free to retract radially inwardly so as to obviatethe formerly present radially outwardly directed biasing force acting onits associated wheel 42 which served to maintain wheel 42 in drivingcooperation with the pipeline interior.

As will be recognized, motor or positioning means 54 may be of theautomatic self-retracting type which would serve, when air pressure wasreduced in its interior, to automatically retract plate 39. Where suchautomatic retraction was to be effected, the piston rod 56 would beconnected with the bracket 50 or some other element associated withplate 39 or possibly plate 39 itself.

As will be recognized, each of the drive wheel assemblies 30 willfunction in the manner heretofore described, with the three assembliesbeing simultaneously extendable in response to the supplying ofpressurized air to manifold 34.

As will also be appreciated, the drive wheels 42 in the three assemblies30 depicted in FIG. 6 will be generally concurrently actuated or rotatedfor propelling purposes in response to the supplying of pressurized airto manifold 24.

Thus, the supplying of pressurized air to manifold 24 by pressurized airsource 26 will serve to concurrently actuate the previously notedoperating components of the unit 19 and:

I. operate latch means 25 so as to secure source 26 with detector 19;

2. bias drive means, i.e. wheels 42, radially outwardly intofrictionally interacting and driving cooperation with the pipelineinterior; and

3. actuate or operate wheel means 42 so as to induce propelling of thedetector 19 through the pipeline intenot.

As will also be appreciated, the reduction of pressure in conduit 26,for example, which may be effected by venting the conduit on vessel 2 tothe atmosphere, will concurrently serve to:

l. deactivate latch means 25 so as to pennit or effect the separation ofconduit means 26 and detector 19;

2. remove the radially outwardly directing biasing force acting on wheelmeans 42 (which may be considered as retraction of the wheel means); and

3. deactivate the drive motors 54 associated with wheel means 42.

CENTERING WHEELS With the mode of operation of the propulsion systemhaving been reviewed, it now becomes appropriate to consider structuralaspects of the centering wheel assemblies 28.

A representative wheel assembly 28 is shown in FIG. 1 1

As there shown, each assembly 28 includes a body 57 which is connectedto its associated disc by a bracket means 58. A telescoping innercomponent 59 is reciprocably mounted within the body 52.

As shown in FIGS. 5 and 7, each body 57 is generally radially orientedso as to permit generally radially oriented movement of the component59.

A coil spring 60 contained within body 52 may exert a radially outwardlydirected biasing force on each element 59, when the element 59 has beenmoved radially inwardly of body 52 in response to insertion of unit 19into the interior of pipeline 7.

If desired, a retaining pin or rod 61 may be connected with component59. Such a rod would be telescopable through an inner end wall ofhousing 57 and have a headed end 61a to limit outward movement ofcomponent 59.

As shown in FIG. 11, each component 59 carries at its outer end acentering wheel 62.

The yieldably biased nature of the wheel 62, as provided by the actionof spring means 60, will serve to ensure that the wheels 62 of thevarious assemblies 28 are concurrently brought into centeringcooperation with the pipeline interior.

The cooperative interaction of the various wheel means 62 will thusserve to maintain an appropriate, limited clearance between peripheriesof discs 21 and 22 and the pipeline interior, at least where anunbuckled pipeline interior is involved.

PIPELINE CONDITION DETECTING OPERATION The structural and operatingcharacteristics of detector 19 having been reviewed, it now becomespossible to consider the overall manner in which the invention ispracticed so as to enable the detector 19 to perform a pipeline scanningfunction during the pipeline laying operation itself.

As will be appreciated from the foregoing discussion, this operationwill be conducted while tensioning means 3 remains engaged with pipelineportion 7b. This engagement of the tensioning means 3 with pipelineportion 7b will be such as to enable the tensioning means 3 to operateto retrieve the pipeline in the event that a buckle condition isdetected.

This mode of retrieval is described, for example, in Lawrence U.S. Pat.No. 3,390,532.

Such retrieval could be effected, for example, when the detector 19, inmoving through an increment of the submerged pipeline portion(ordinarily a newly added increment of portion 7a), would detect abuckle condition in such an increment. When the buckle was detected, thetensioning means would be operated so as to exert a sufficienttensioning force on the pipeline portion 7b as to retrieve enough of thepreviously laid pipeline so as to bring the increment containing thebuckle on board the vessel 2. This retrieval of the pipeline incrementcontaining the buckle would also entail the concurrent retrieval of thedetector 19 itself.

When the tensioned or buckled increment was on board vessel 2, it wouldbe repaired or replaced, and pipeline laying reinitiated. The detectorwould be relocated and scanning resumed, employing the operationaltechniques now to be described.

CONDITION DETECTING This invention pertains to the detecting of anirregular or adverse condition, or an acceptable condition, in a portionof a submerged pipeline and may commence with an installation as shownin FIG. 111.

With system elements disposed as shown in FIG. la, the initially laidfirst portion 7a of a pipeline is supported on a submergedsurface 16while a second portion 7b is supported by the tensioning means 3 on thevessel 2. The tensioning means 3 is concurrently operable to implementlaying of the pipeline under tension or effect retrieval of thepreviously laid pipeline for repair purposes.

A third pipeline portion 7c extends through the body of water 15 betweenthe first pipeline portion 7a and the second pipeline portion 7b.

As shown in FIG. 1a, when detecting is to be initiated, the detectingmeans 19 may be positioned within the interior of the extremity of thepipeline portion 7b on lay barge 2, with the draft means 20 connectedwith means 19 and extending possibly from a coil or pneumatic winchmechanism, schematically depicted by the reference numeral 63. Operatorson board the vessel 2 would position the flange 32 of the air hose 26adjacent the flange 31 of the detecting means 19. By supplyingpressurized air through the hose 26, the latch means 25 would beactuated so as to detachably interconnect the source 26 of pressurizedair with the detecting means 19 and activate propulsion wheels 42. Thisactuation would include (1) substantially concurrent actuation of thevarious drive wheel extending motor means 54 so as to bias the wheels 42outwardly into driving engagement with the pipeline interior and (2)substantially concurrent actuation of the motor means 49 so as to inducepropelling rotation of the wheel means 42.

By appropriately paying out" the air hose 26 and draft means 20, thedetecting means-will propel itself through the interior of the pipeline7 until an operator determines, based on known profile characteristicsof the pipeline, that the detecting means 19 has come to a rest eitherwithin the first pipeline portion 7a or possibly within anothersubmerged pipeline portion. For example, the detecting means might beinitially positioned in the vicinity of the junction 18 between pipe--line portions 7a and 70, or even within the pipeline portion 70,depending upon the condition being detected.

After the appropriate position of the detecting means 19 within thepipeline interior has been effected, possibly as generally shown in FIG.lb, the pressure of air within air hose 26 would be reduced so as topermit the decoupling of hose 26 and detecting means 19 in the mannerpreviously described. FIG. lb depicts the flange terminus 32 of the airhose 26 within pipeline portion 7:: during the retrieving or recoilingoperation of this air hose, possibly as implemented by winch means 63.

A portion of the flexible draft means 20 would then be disconnected fromcoil means 63 and be connected with a pipeline alignment means or lineup clamp 10 as schematically shown in FIG. 10.

The line up clamp would then be positioned within the interior of thepipeline, possibly generally as shown in FIG. 2c. r

A first additional pipeline segment or increment (i.e. joint) would thenbe manipulated into position in axial alignment with the pipelineterminus and the alignment clamp 10 might then be drawn back into theposition shown schematically in FIG. 2a where it would be aligned withthe junction 13 between pipeline body 7 and new joint 9.

This manipulation could be facilitated by a cable or rope connected withthe air pipe 12, with the cable or hose being threaded through the newjoint 9 to permit alignment means 11 to be drawn into the FIG. 2aposition.

With the components disposed as shown in FIG. 2a, the detecting means 19is connected by flexible draft means to the pipeline alignment means 10.Concurrently, this pipeline alignment means is interconnecting thepipeline portion 7b in longitudinal alignment with the additionalpipeline increment 9.

With the components disposed as shown in FIG. 2a, air would be suppliedthrough branch conduit 14 to air pipe 12, as permitted by valve 15, soas to actuate the alignment means 10 and maintain its clamps in aligningcooperation with the joint 9 and pipeline body 7.

During this operation, a flexible cable or rope 64 extending from coilor winch means 63 may be detachably connected with the air pipe 12.

After the welding operation at station 8 has been completed, the layingbarge 2 would move ahead, i.e. away from the previously laid pipelinesegments, so as, in essence, to displace the increment 9 into the firstpipeline portion 7a as shown schematically in FIG. 2b.

During this movement, the line up clamp 10 may remain in its expanded oractuated condition by virtue of a closed condition of valve 15 servingto entrap pressurized air within pipe 12 and line up clamp or alignmentmeans 10. Alternatively, valve 15 may be open and pipe 12 disconnectedfrom air source 14. Under these circumstances, the clamps of mechanism10 would be retracted and mechanism 10 would be frictionally immobilizedwithin pipeline portion 7b.

During this movement, which constitutes a part of the laying operation,the tensioning means 3 would maintain appropriate control tension on thepipeline.

During the movement operation depicted in FIG. 2b, not only may the airconduit 14 be uncoupled from the pipe 12, but the rope or cable 64 maybe disengaged from the air pipe.

With the components disposed as shown in FIG. 2b, conventionaltechniques may be employed to bring a second additional pipelineincrement 65 into position in longitudinal alignment with the firstadditional increment. This first increment, being at least partiallywelded or secured to the pipeline body, now comprises a terminus of thesecond pipeline portion 7b.

Throughout this operation, pipeline portion 7b, as well as secondincrement 65, would be appropriately supported by roller or cradle means6, most of which are not shown.

With the components disposed as shown in FIG. 2c, a section of cable orrope 66 may be threaded through the interior of joint 65 and connectedwith line 64 and the end of air pipe 12. The valve 15, if closed, may beopened so as to effect retraction of the clamps in mechanism 10. Priorto retracting the clamp means 10, the winch means 63 may be operated soas to take the slack out of the interconnected draft means 64 and 66.

The winch means 63 may then be operated to move the alignment means 10generally toward the new joint 65 and into position in aligningcooperation with the juncture 67 between the joint 9 and the joint 65.

Thus, this movement of the alignment means 10, schematically depicted inFIG. 2d, will thus serve to cause the detecting means 19 to move, orattempt to move, generally toward an additional increment of thepipeline portion 7a which has moved into the pipeline zone 7a as aresult of the advancing movement of the barge 2 described in connectionwith FIG. 2b. The movement of the barge described in connection withFIG. 2b, of course, served to cause an additional increment of thepipeline to come to rest on the submerged surface 16 so as to, inessence, extend the length of pipeline portion 7a, i.e. cause anadditional increment to move into the zone designated 70.

In other words, during the retracting movement of the line up clamp oralignment means 10, the draft means 20 would have exerted a retractingor pulling force on the detecting means 19. This pulling force wouldhave caused the detecting means 19 to move, or attempt to move, withinthe interior of the submerged pipeline, generally toward the vessel 2and second pipeline portion 7b and through a recently or newly addedincrement of portion 7a. This movement would have permitted the detectorto thus scan the interior of such an increment of the pipeline portion7a, with a view to detecting irregularities such as a buckle condition.

In the event that a buckle condition is detected (due to an inability tomove unit 19 because of engagement of disc 21 with a buckle), thetensioning means 3 may be operated to retrieve the incrementcontaining'the buckle condition and the detector means 19 so thatappropriate repairs may be initiated and pipelaying and conditiondetecting resumed.

In the event that no irregularity is detected by the de-' tecting means'19, the alignment means 10 will be positioned at joint juncture 67, asshown in FIG. 2d, so as to permit the additional segment 65 to bedisposed in generally abutting and longitudinally aligned relation withthe joint 9 so that interconnection or welding of joints 9 and 65 may beeffected. When the welding at illustrated station 8, between alignedsections 9 and 65, is terminated, the sequence of operations heretoforedescribed may be resumed.

As will be appreciated, prior to effecting the welding of joints 9 and65, the air hose 14 would be reconnected with the air pipe 12 and thevalve 15 opened to effect the actuation of the line up clamp elements inthe mechanism 10.

While in many operations the welding at station 8 would involve theformation of an initial bead so as to weldingly and at least partiallyinterconnect the joints 9 and 65, under certain circumstances, automatedwelding equipment may effect substantial or complete welding of thejoints 9 and 65 at the single welding station shown in FIGS. 2a and 2d.

Optimum benefits of the invention are realized where the scanning deviceor detecting means 19 is disposed in pipeline portion 7a reasonably nearthe tangency point 18. This disposition of the detecting means 19 willensure that the scanning movement of the detecting means 19 will takeplace through the most recently added increment or increments of thepipeline which have come to rest on the submerged surface 16. Followingthis technique, scanning of pipeline increments which have passedthrough the zone 7b and 7c, where buckling might occur, will be effectedat the earliest moment so that repairs may be made as expeditiously aspossible.

Depending upon operating conditions, the detecting means 19 may effectscanning of additional increments added to pipeline portion 7a somewhatafter or before the point in time that such increments have come to reston the submerged surface 16.

ALTERNATIVE SCANNING TECHNIQUE The scanning technique heretoforedescribed is effected between incrementsv of lay barge movement whichserve to cause pipeline laying on surface 16.

In other words, as the lay barge 2 is moved ahead so as to displace thejoint 9 from the FIG. 2a to the FIG. 2b positions, an additionalincrement of pipeline will be added to the pipeline portion 7a, i.e. thesubmerged and suspended profile of the pipeline will translate along thelaying route so as to cause an additional increment of the pipeline tocome to rest on the submerged surface 16 within the zone designated asfirst pipeline portion 7a.

Those skilled in the pipelaying art and familiar with the disclosurewill recognize that the invention might also be practiced by securingthe detecting means 19, as for example by connecting it with astationaryor immobilizeddrum of winch means 63, during the pipelaying or advancingmovement of the lay barge.

Under these circumstances, the advancing movement of the lay barge wouldexert a pulling force on unit 19,

through the draft means 20, so as to cause scanning means I9 to moverelative to the pipeline during the actual advancing or laying movementof the lay barge itself.

In any event, regardless of which scanningtechnique is employed, thepresent invention contemplates that scanning or detecting operationswill be performed during the laying operation, that is to say, betweenthe termination and initiation of the laying of the complete pipeline 7and while the retrieving means 3 of the lay barge 2 remains continuouslyoperable to effect retrieval of a defective'pipeline section.

SUMMARY OF MAJOR ADVANTAGES AND OVERALL SCOPE OF INVENTION A principaladvantage of the invention resides in the provision of a technique whichenables defects in submerged pipelines to be detected during the layingoperation.

Defects may be determined almost as soon as a defective section has cometo rest on the submerged surface so as to enable repairs to be made asexpeditiously as possible.

Significantly, condition detecting is effected while the lay barge orfloating vessel means remains continuously operable to retrieve adefective section for repair operations. Where the retrieval is effectedby the tensioning means, i.e. utilizing the pipelaying equipment itself,proper and effective control over pipeline stress may be maintained soas to minimize the chance of causing pipeline tension during therepairing operation.

The necessity of resorting to underwater repairs or costly repairsinitiated after pipeline laying has been completed may be avoided.

The technique described heretofore enables an operator to ensure acustomer at the completion of the laying operation, without furtherdelay, that the pipeline has been scanned for certain abnormalities andis in an acceptable condition. In this manner, delays involvingsubsequent inspection operations are avoided and the pipeline may beplaced in operating condition more quickly. Such savings in time areparticularly significant where weather conditions or other factors limitthe time available to complete pipeline laying operations and placepipelines in operating condition.

In performing these detecting or scanning operations concurrently withthe pipelaying operation itself, a substantial savings in time and moneyis effected.

The propulsion mechanism described in connection with the detectingmechanism of the present invention is uniquely advantageous in that itpermits a propulsion power source to be effectively deactivated andremoved from the pipeline interior once the detecting means has beenappropriately located.

A variety of modified aspects of the invention have been heretofore setforth. In summary, it will be recognized that the invention may bepracticed by:

l. employing substantial variations in pipeline laying techniques andequipment;

2. detecting a wide variety of pipeline conditions;

3. performing detecting operations with a wide variety of detectingapparatus; and

- 4. conducting the detecting operation itself either in betweenincrements of lay barge movement or concurrent with lay barge movement,or possibly in both ways.

Such variations are indicative of the scope of the invention and it willbe apparent to those skilled in the pipelaying art and familiar withthis disclosure that such variations and other additions, deletions,substitutions, and modifications may be made within the scope of theinvention as set forth in the appended claims.

What is claimed is: 1. A method of detecting a submerged pipelinecondition, said method comprising: I supporting a pipeline at anoffshorelocation with a first portion supported on a submerged surface, a secondportion supported on floating vessel means, and a third portionextending through a body of water between said first and second pipelineportions; positioning pipeline condition detecting means within theinterior of a submerged portion of said pipeline; increasing the lengthof said pipeline from said floating vessel means so as to provide anadditional submerged pipeline increment, and while the pipeline ofincreased length remains supportedby said floating vessel means andwhile said pipeline condition detecting means remains within theinterior of a submerged portion of the pipeline of increased length,inducing relative movement between the additional submerged pipelineincrement and said pipeline condition detecting means, and detecting acondition of said additional submerged pipeline increment with saiddetecting means; said floating vessel means being operable to retrievesaid additional submerged pipeline increment by exerting a retrievingforce on said second pipeline portion. 2. A method of detecting asubmerged pipeline condition, said method comprising:

supporting a pipeline at an offshore location with a first portionsupported on a submerged surface, a second portion supported on floatingvessel means, and

a third portion extending through a body of water between said first andsecond pipeline portions; engaging said second pipeline portion bypipeline tensioning means on said floating vessel means; supporting saidthird pipeline portion, at least in part, by at least partiallysubmerged buoyant ramp means extending from and connected with saidfloating vessel means; positioning pipeline condition detecting meanswithin the interior of a submerged portion of said pipeline; inducingrelative movement between said first pipeline portion and said pipelinedetecting means by flexible draft means extending from said pipelinedetecting means through the interior of said third pipeline portion,over said buoyant ramp means, and through the interior of said secondpipeline portion engaged by said pipeline tensioning means on saidfloating vessel means; and detecting a condition of said submergedpipeline portion with said detecting means while the pipeline remainssupported by said floating vessel means;

said pipeline tensioning means on said floating vessel means beingcontinuously operable to retrieve said first pipeline portion on boardsaid floating vessel means by exerting a retrieving force on said secondpipeline portion so as to displace an increment of said first pipelineportion into said second pipeline portion through movement of saidincrement upwardly through said body of water, over said buoyant rampmeans, and onto said floating vessel means.

3. A method as described in claim 1, wherein:

the step of inducing relative movement between said pipeline conditiondetecting means and said additional submerged pipeline incrementresponsively causes detection by said detecting means of a bucklecondition in said increment of said pipeline; and wherein a retrievingforce is exerted on said second pipeline portion to retrieve saidincrement of said pipeline containing said detected buckle condition onboard said floating vessel means.

4. A method of detecting a dimensional irregularity in an internal crosssection of a submerged pipeline portion, said method comprising:

supporting a pipeline at an offshore location with a first pipelineportion supported on a submerged surface,

a second pipeline portion supported on floating vessel means, and

a third pipeline portion extending through a body of water between saidfirst and second pipeline portions;

propelling pipeline detecting means from said floating vessel meanssequentially through said second and third pipeline portions to positionsaid pipeline detecting means within the interior of said first pipelineportion;

said pipeline detecting means, when disposed within the interior of saidfirst pipeline portion, being operable to detect an irregularity indimension in the cross section of said pipeline in response to relativemovement between said pipeline detecting means and said first pipelineportion;

Ell

increasing the length of said pipeline from said floating vessel meansso as to provide an additional pipeline increment in said first pipelineportion;

from said floating means, inducing relative movement between saidpipeline detecting means and said additional increment of said firstpipeline portion, with said relative movement being operable to permitsaid pipeline detecting means to detect a dimensional irregularity inthe cross section of said additional increment of said first pipelineportion; and

providing pipeline retrieving means on said floating means operable toretrieve said additional increment of said first pipeline portion in theevent that said pipeline detecting means should detect a dimensionalirregularity in the cross section of said additional increment of saidfirst pipeline portion.

5. A method as described in claim 4:

wherein said second pipeline portion is engaged by pipeline tensioningmeans on said floating vessel means;

wherein said third pipeline portion is supported, at

least in part, by at least partially submerged buoyant ramp meansextending from and connected with said floating vessel means; and

wherein said method additionally comprises inducing relative movementbetween said first pipeline portion and said pipeline detecting means byflexible draft means extending from said pipeline detecting meansthrough the interior of said third pipeline portion, over said buoyantramp means, and through the interior of said second pipeline portionengaged by said pipeline tensioning means on said floating vessel means;

said pipeline tensioning means being continuously operable to retrievesaid first pipeline portion on board said floating vessel means byexerting a retrieving force on said second pipeline portion so as todisplace an increment of said first pipeline portion into said secondpipeline portion through movement of said increment upwardly throughsaid body of water, over said buoyant ramp means, and onto said floatingvessel means.

6. A method as described in claim 5, wherein:

the step of inducing relative movement between said pipeline detectingmeans and said additional increment of said first pipeline portionresponsively causes detection by said detecting means of a bucklecondition in said additional increment; and wherein a retrieving forceis exerted on said second pipeline portion by said pipeline tensioningmeans to retrieve said additional increment of first pipeline portioncontaining said detected buckle condition on board said floating vesselmeans.

7. A method of detecting a dimensional irregularity in an internal crosssection of a submerged pipeline portion, said method comprising:

supporting a pipeline at an offshore location with a first pipelineportion supported on a submerged surface,

a second pipeline portion supported on floating vessel means, and

a third pipeline portion extending through a body of water between saidfirst and second pipeline portions;

propelling pipeline detecting means from said floating vessel meanssequentially through said second and third pipeline portions to positionsaid pipeline detecting means within the interior of said first pipelineportion;

, said pipeline detecting means, when disposed within the interior ofsaid first pipeline portion, being operable to detect an irregularity indimension in the cross section of said pipeline in response to relativemovement between said pipeline detecting means and said first pipelineportion; connecting said pipeline detecting means with pipeline sectionalignment means; on said floating vessel means operating said pipelinesection alignment means to generally secure in longitudinal alignment afirst additional pipeline section with a terminus of said secondpipeline portion; weldingly, and at least partially, interconnectingsaid first additional pipeline section and said second pipeline portionterminus, with said pipeline section alignment means securing said firstadditional pipeline section and said second pipeline portion terminus inlongitudinal alignment, and remaining connected with said pipelinedetecting means; advancing said first additional pipeline section onsaid floating vessel means toward said body of water, with said pipelinedetecting means remaining connected with said pipeline section alignmentmeans, and said pipeline section alignment means interconnecting andaligning said first additional pipeline section and said second pipelineportion terminus; said advancing of said additional pipeline section onsaid floating vessel means being operable to increase the length of saidfirst pipeline portion and provide an additional pipeline increment insaid first pipeline portion; positioning a second, additional pipelinesection in general longitudinal alignment with said first additionalpipeline section; moving said pipeline section alignment means towardsaid second additional pipeline section, away from said first additionalpipeline section: said movement of said pipeline section alignment meansaway from said first additional pipeline section causing said pipelinedetecting means to move generally toward said additional increment ofsaid first pipeline portion, with this movement being operable to permitsaid pipeline detecting means to detect a dimensional irregularity inthe cross section of said first pipeline portion; said movement of saidpipeline section alignment means away from said first additionalpipeline section being operable to position said pipeline sectionalignment means in position to secure, in mutual longitudinal alignment,a terminus of said first additional pipeline section and a terminus ofsaid second additional pipeline section; and providing pipelineretrieving means on said floating means operable to retrieve anincrement of said first pipeline portion in the event that said pipelinedetecting means should detect a dimensional irregularity in the crosssection of said first pipeline portion.

8. A method as described in claim 7:

wherein said second pipeline portion is engaged by pipeline tensioningmeans on said floating vessel means;

wherein said third pipeline portion is supported, at

least in part, by at least partially submerged buoyant ramp meansextending from and connected with said floating vessel means; and

wherein said method additionally comprises inducing relative movementbetween said first pipeline portion and said pipeline detecting means byflexible draft means connected with said pipeline section alignmentmeans and extending from said pipeline detecting means through theinterior of said third pipeline portion, over said buoyant ramp means,and through the interior of said second pipeline portion engaged by saidpipeline tensioning means on said floating vessel means;

said pipeline tensioning means being continuously operable to retrievesaid first pipeline portion on board said floating vessel means byexerting a retrieving force on said second pipeline portion so as todisplace an increment of said first pipeline portion into said secondpipeline portion through movement of said increment upwardly throughsaid body of water, over said-buoyant ramp means, and onto said floatingvessel means.

9. A method as described in claim 8, wherein said pipeline detectingmeans is propelled from said floating vessel means to said firstpipeline portion by:

pneumatically operating latch means to interconnect a source ofpressurized air with said pipeline detecting means;

in response to said interconnection of said source of pressurized airwith said pipeline detecting means, i extending drive means carried bysaid pipeline detecting means into driving engagement with the interiorof said pipeline, and operating said drive means so as to exert apropelling force on the interior of said pipeline tending to propel saidpipeline detecting means toward said first pipeline portion; in responseto operation of said drive means, propelling said pipeline detectingmeans from said floating vessel means sequentially through said secondand third pipeline portion to said first pipeline portion; reducing thepressure of said pressurized air and in response to said reduction ofpressure disconnecting said source of pressurized air from said pipelinedetecting means, retracting said drive means out of driving engagementwith the interior of said pipeline means, and discontinuing operation ofsaid drive means; and retrieving said source of pressurized air fromsaid pipeline detecting means sequentially through said second and thirdpipeline portions to said floating vessel means.

10. A method as described in claim 9, wherein:

the step of inducing relative movement between said pipeline detectingmeans and said additional increment of said first pipeline portionresponsively causes detection by said detecting means of a bucklecondition in said additional increment; and wherein a retrieving forceis exerted on said second pipeline portion by said pipeline tensioningmeans to retrieve said additional increment of first pipeline portioncontaining said detected buckle condition on board said floating vesselmeans.

11. Apparatus for detecting a submerged pipeline condition, saidapparatus comprising:

floating vessel means operable to support, at least in part, a pipelineat an offshore location with a first portion supported on a submergedsurface, a second portion supported on floating vessel means, and athird portion extending through a body of water between said first andsecond pipeline portions; pipeline condition detecting means positionedwithin the interior of a submerged portion of said pipeline; saidfloating vessel means being operable to increase the length of saidpipeline so as to provide an additional submerged pipeline increment;

means for inducing relative movement between the additional submergedpipeline increment and said detecting means, while said detecting meansremains within the interior of a submerged portion of pipeline and whilesaid pipeline remains supported, at least in part, by said floatingvessel means;

said pipeline detecting means being operable to detect a condition ofsaid additional submerged pipeline increment while said pipeline remainssupported at least in part, by said floating vessel means;

said floating vessel means being operable to retrieve said additionalsubmerged pipeline increment by exerting a retrieving force on saidsecond pipeline portion. I

12. Apparatus for detecting a submerged pipeline condition, saidapparatus comprising:

floating vessel means operable to support, at least in part, a pipelineat an offshore location with a first portion supported on a submergedsurface, a second portion supported on floating vessel means, and athird portion extending through a body of water between said first andsecond pipeline portions; pipeline condition detecting means positionedwithin the interior of a submerged portion of said pipeline; saidpipeline detecting means being operable to detect a condition of saidsubmerged pipeline portion while said pipeline remains supported atleast in part, by said floating vessel means;

pipeline tensioning means on said floating vessel means operable toengage said second pipeline portion; I

at least partially submerged buoyant ramp means extending from andconnected with said floating vessel means and supporting, at least inpart, said third pipeline portion; and

flexible draft means extending from said pipeline detecting meansthrough the interior of said third pipeline portion, over said buoyantramp means, and through the interior of said second pipeline portionengaged by said pipeline tensioning means on said floating vessel means,said flexible draft means being operable to induce relative movementbetween said first pipeline portion and said pipeline detecting means;and

said pipeline tensioning means on said floating vessel means beingcontinuously operable to retrieve said first pipeline portion on boardsaid floating vessel means by exerting a retrieving force on said secondpipeline portion so as to displace an increment of said first pipelineportion into said second pipeline portion through movement of saidincrement upwardly through said body of water, over said buoyant rampmeans, and onto said floating vessel means.

13. Apparatus as described in claim 11, wherein:

said pipeline condition detecting means comprises means operable, inresponse to relative movement between said pipeline detecting means andsaid pipeline, to detect a buckle condition in said pipeline.

14. Apparatus for detecting a dimensional irregularity in an internalcross section of a submerged pipeline portion, said apparatuscomprising:

floating vessel means operable to support, at least in part, a pipelineat an offshore location with a first pipeline portion supported on asubmerged surface,

a second pipeline portion supported on floating vessel means, and

a third pipeline portion extending through a body of water between saidfirst and second pipeline portions;

pipeline detecting means;

means for propelling said pipeline detecting means from said floatingvessel means sequentially through said second and third pipelineportions to position said pipeline detecting means within the interiorof said first pipeline portion;

said pipeline detecting means, when disposed within the interior of saidfirst pipeline portion, being operable to detect an irregularity indimension in the cross section of said pipeline in response to relativemovement between said pipeline detecting means and said first pipelineportion;

means for increasing the length of said pipeline from said floatingvessel means so as to provide an additional pipeline increment in saidfirst pipeline portion; means operable from said floating means toinduce relative movement between said pipeline detecting means and saidadditional increment of said first pipeline portion, with said relativemovement being operable to permit said pipeline detecting means todetect a dimensional irregularity in the cross section of saidadditional increment of said first pipeline portion; and

pipeline retrieving means on said floating means operable to retrievesaid additional increment of said first pipeline portion in the eventthat said pipeline detecting means should detect a dimensionalirregularity in the cross section of said additional increment of saidfirst pipeline portion.

15. A method as described in claim 14 including:

pipeline tensioning means on said floating vessel means operable toengage said second pipeline portion;

at least partially submerged buoyant ramp means extending from andconnected with said floating vessel means and supporting, at least inpart, said third pipeline portion;

flexible draft means extending from said pipeline detecting meansthrough the interior of said third pipeline portion, over said buoyantramp means,

and through the interior of said second pipeline portion engaged by saidpipeline tensioning means on said floating vessel means;

said flexible draft means being operable to induce relative movementbetween said first pipeline portion and said pipeline detecting means;and

said pipeline tensioning means being continuously operable to retrievesaid first pipeline portion on board said floating vessel means byexerting a retrieving force on said second pipeline portion so as todisplace an increment of said first pipeline portion into said secondpipeline portion through movement of said increment upwardly throughsaid body of water, over said buoyant ramp means, and onto said floatingvessel means.

16. Apparatus as described in claim 15, wherein:

said pipeline detecting means comprises means operable, in response torelative movement between said pipeline detecting means and saidadditional increment of said first pipeline portion, to detect a bucklecondition in said additional increment.

17. Apparatus for detecting a dimensional irregularity in an internalcross section of a submerged pipeline portion, said apparatuscomprising:

floating vessel means operable to support, at least in part, a pipelineat an offshore location with a first pipeline portion supported on asubmerged portion, a second pipeline portion supported on floatingvessel means, and a third pipeline portion extending through a body ofwater between said first and second pipeline portions; pipelinedetecting means; propelling means for propelling said pipeline detectingmeans from said floating vessel means sequentially through said secondand third pipeline portions to position said pipeline detecting meanswithin the interior of said first pipeline portion;

said pipeline detecting means, when disposed within the interior of saidfirst pipeline portion, being operable to detect an irregularity indimension in the cross section of said pipeline in response to relativemovement between said pipeline detecting means and said first pipelineportion; pipeline section alignment means; means operable to connectsaid pipeline detecting means with pipeline section alignment means;

said pipeline section alignment means being operable to generally securein longitudinal alignment a first additional pipeline section with aterminus of said second pipeline portion;

welding means operable to at least partially interconnect said firstadditional pipeline section and said second pipeline portion terminus,with said pipeline section alignment means securing said firstadditional pipeline section and said second pipeline portion terminus inlongitudinal alignment, and

remaining connected with said pipeline detecting means;

means for advancing said first additional pipeline section on saidfloating vessel means toward said body of water, with saidpipelincdetecting means remaining connected with said pipeline section alignmentmeans, and

said pipeline section alignment means interconnecting and aligning saidfirst additional pipeline section and said second pipeline portionterminus; said advancing of said additional pipeline section on saidfloating vessel means being operable to increase the length of saidfirst pipeline portion and provide an additional pipeline increment insaid first pipeline portion; means for positioning a second, additionalpipeline section in general longitudinal alignment with said firstadditional pipeline section; means for moving said pipeline sectionalignment means toward said second additional pipeline section, awayfrom said first additional pipeline section; said movement of saidpipeline section alignment means away from said first additionalpipeline section causing said pipeline detecting means to move generallytoward said additional increment of said first pipeline portion, withthis movement being operable to permit said pipeline detecting means todetect a dimensional irregularity in the cross section of said firstpipeline portion; said movement of said pipeline section alignment meansaway from said first additional pipeline section being operable toposition said pipeline section alignment means in position to secure, inmutual longitudinal alignment, a terminus of said first additionalpipeline section and a terminus of said second additional pipelinesection; and pipeline retrieving means on said floating means operableto retrieve an increment of said first pipeline portion in the eventthat said pipeline detecting means should detect a dimensionalirregularity in the cross section of said first pipeline portion. 18.Apparatus as described in claim 17: pipeline tensioning means includedin said floating vessel means operable to engage said second pipelineportion; at least partially submerged buoyant ramp means extending fromand connected with said floating vessel means and supporting, at leastin part, said third pipeline portion; flexible draft means connectedwith said pipeline section alignment means and extending from saidpipeline detecting means through the interior of said third pipelineportion, over said buoyant ramp means, and through the interior of saidsecond pipeline portion engaged by said pipeline tensioning means onsaid floating vessel means, said flexible draft means being operable toinduce relative movement between said first pipeline portion and saidpipeline detecting means; and said pipeline tensioning means beingcontinuously operable to retrieve said first pipeline portion on boardsaid floating vessel means by exerting a retrieving force on said secondpipeline portion so as to displace an increment of said first pipelineportion into said second pipeline portion through movement of saidincrement upwardly through said body of water, over said buoyant rampmeans, and onto said floating vessel means. 19. Apparatus as describedin claim 18, wherein said propelling means comprises:

a source of pressurized air;

1. A method of detecting a submerged pipeline condition, said methodcomprising: supporting a pipeline at an offshore location with a firstportion supported on a submerged surface, a second portion supported onfloating vessel means, and a third portion extending through a body ofwater between saId first and second pipeline portions; positioningpipeline condition detecting means within the interior of a submergedportion of said pipeline; increasing the length of said pipeline fromsaid floating vessel means so as to provide an additional submergedpipeline increment, and while the pipeline of increased length remainssupported by said floating vessel means and while said pipelinecondition detecting means remains within the interior of a submergedportion of the pipeline of increased length, inducing relative movementbetween the additional submerged pipeline increment and said pipelinecondition detecting means, and detecting a condition of said additionalsubmerged pipeline increment with said detecting means; said floatingvessel means being operable to retrieve said additional submergedpipeline increment by exerting a retrieving force on said secondpipeline portion.
 2. A method of detecting a submerged pipelinecondition, said method comprising: supporting a pipeline at an offshorelocation with a first portion supported on a submerged surface, a secondportion supported on floating vessel means, and a third portionextending through a body of water between said first and second pipelineportions; engaging said second pipeline portion by pipeline tensioningmeans on said floating vessel means; supporting said third pipelineportion, at least in part, by at least partially submerged buoyant rampmeans extending from and connected with said floating vessel means;positioning pipeline condition detecting means within the interior of asubmerged portion of said pipeline; inducing relative movement betweensaid first pipeline portion and said pipeline detecting means byflexible draft means extending from said pipeline detecting meansthrough the interior of said third pipeline portion, over said buoyantramp means, and through the interior of said second pipeline portionengaged by said pipeline tensioning means on said floating vessel means;and detecting a condition of said submerged pipeline portion with saiddetecting means while the pipeline remains supported by said floatingvessel means; said pipeline tensioning means on said floating vesselmeans being continuously operable to retrieve said first pipelineportion on board said floating vessel means by exerting a retrievingforce on said second pipeline portion so as to displace an increment ofsaid first pipeline portion into said second pipeline portion throughmovement of said increment upwardly through said body of water, oversaid buoyant ramp means, and onto said floating vessel means.
 3. Amethod as described in claim 1, wherein: the step of inducing relativemovement between said pipeline condition detecting means and saidadditional submerged pipeline increment responsively causes detection bysaid detecting means of a buckle condition in said increment of saidpipeline; and wherein a retrieving force is exerted on said secondpipeline portion to retrieve said increment of said pipeline containingsaid detected buckle condition on board said floating vessel means.
 4. Amethod of detecting a dimensional irregularity in an internal crosssection of a submerged pipeline portion, said method comprising:supporting a pipeline at an offshore location with a first pipelineportion supported on a submerged surface, a second pipeline portionsupported on floating vessel means, and a third pipeline portionextending through a body of water between said first and second pipelineportions; propelling pipeline detecting means from said floating vesselmeans sequentially through said second and third pipeline portions toposition said pipeline detecting means within the interior of said firstpipeline portion; said pipeline detecting means, when disposed withinthe interior of said first pipeline portion, being operable to detect anirregularity in dimension in the cross section of said pipeliNe inresponse to relative movement between said pipeline detecting means andsaid first pipeline portion; increasing the length of said pipeline fromsaid floating vessel means so as to provide an additional pipelineincrement in said first pipeline portion; from said floating means,inducing relative movement between said pipeline detecting means andsaid additional increment of said first pipeline portion, with saidrelative movement being operable to permit said pipeline detecting meansto detect a dimensional irregularity in the cross section of saidadditional increment of said first pipeline portion; and providingpipeline retrieving means on said floating means operable to retrievesaid additional increment of said first pipeline portion in the eventthat said pipeline detecting means should detect a dimensionalirregularity in the cross section of said additional increment of saidfirst pipeline portion.
 5. A method as described in claim 4: whereinsaid second pipeline portion is engaged by pipeline tensioning means onsaid floating vessel means; wherein said third pipeline portion issupported, at least in part, by at least partially submerged buoyantramp means extending from and connected with said floating vessel means;and wherein said method additionally comprises inducing relativemovement between said first pipeline portion and said pipeline detectingmeans by flexible draft means extending from said pipeline detectingmeans through the interior of said third pipeline portion, over saidbuoyant ramp means, and through the interior of said second pipelineportion engaged by said pipeline tensioning means on said floatingvessel means; said pipeline tensioning means being continuously operableto retrieve said first pipeline portion on board said floating vesselmeans by exerting a retrieving force on said second pipeline portion soas to displace an increment of said first pipeline portion into saidsecond pipeline portion through movement of said increment upwardlythrough said body of water, over said buoyant ramp means, and onto saidfloating vessel means.
 6. A method as described in claim 5, wherein: thestep of inducing relative movement between said pipeline detecting meansand said additional increment of said first pipeline portionresponsively causes detection by said detecting means of a bucklecondition in said additional increment; and wherein a retrieving forceis exerted on said second pipeline portion by said pipeline tensioningmeans to retrieve said additional increment of first pipeline portioncontaining said detected buckle condition on board said floating vesselmeans.
 7. A method of detecting a dimensional irregularity in aninternal cross section of a submerged pipeline portion, said methodcomprising: supporting a pipeline at an offshore location with a firstpipeline portion supported on a submerged surface, a second pipelineportion supported on floating vessel means, and a third pipeline portionextending through a body of water between said first and second pipelineportions; propelling pipeline detecting means from said floating vesselmeans sequentially through said second and third pipeline portions toposition said pipeline detecting means within the interior of said firstpipeline portion; said pipeline detecting means, when disposed withinthe interior of said first pipeline portion, being operable to detect anirregularity in dimension in the cross section of said pipeline inresponse to relative movement between said pipeline detecting means andsaid first pipeline portion; connecting said pipeline detecting meanswith pipeline section alignment means; on said floating vessel meansoperating said pipeline section alignment means to generally secure inlongitudinal alignment a first additional pipeline section with aterminus of said second pipeline portion; weldingly, and at leastpartially, interconnecting said First additional pipeline section andsaid second pipeline portion terminus, with said pipeline sectionalignment means securing said first additional pipeline section and saidsecond pipeline portion terminus in longitudinal alignment, andremaining connected with said pipeline detecting means; advancing saidfirst additional pipeline section on said floating vessel means towardsaid body of water, with said pipeline detecting means remainingconnected with said pipeline section alignment means, and said pipelinesection alignment means interconnecting and aligning said firstadditional pipeline section and said second pipeline portion terminus;said advancing of said additional pipeline section on said floatingvessel means being operable to increase the length of said firstpipeline portion and provide an additional pipeline increment in saidfirst pipeline portion; positioning a second, additional pipelinesection in general longitudinal alignment with said first additionalpipeline section; moving said pipeline section alignment means towardsaid second additional pipeline section, away from said first additionalpipeline section: said movement of said pipeline section alignment meansaway from said first additional pipeline section causing said pipelinedetecting means to move generally toward said additional increment ofsaid first pipeline portion, with this movement being operable to permitsaid pipeline detecting means to detect a dimensional irregularity inthe cross section of said first pipeline portion; said movement of saidpipeline section alignment means away from said first additionalpipeline section being operable to position said pipeline sectionalignment means in position to secure, in mutual longitudinal alignment,a terminus of said first additional pipeline section and a terminus ofsaid second additional pipeline section; and providing pipelineretrieving means on said floating means operable to retrieve anincrement of said first pipeline portion in the event that said pipelinedetecting means should detect a dimensional irregularity in the crosssection of said first pipeline portion.
 8. A method as described inclaim 7: wherein said second pipeline portion is engaged by pipelinetensioning means on said floating vessel means; wherein said thirdpipeline portion is supported, at least in part, by at least partiallysubmerged buoyant ramp means extending from and connected with saidfloating vessel means; and wherein said method additionally comprisesinducing relative movement between said first pipeline portion and saidpipeline detecting means by flexible draft means connected with saidpipeline section alignment means and extending from said pipelinedetecting means through the interior of said third pipeline portion,over said buoyant ramp means, and through the interior of said secondpipeline portion engaged by said pipeline tensioning means on saidfloating vessel means; said pipeline tensioning means being continuouslyoperable to retrieve said first pipeline portion on board said floatingvessel means by exerting a retrieving force on said second pipelineportion so as to displace an increment of said first pipeline portioninto said second pipeline portion through movement of said incrementupwardly through said body of water, over said buoyant ramp means, andonto said floating vessel means.
 9. A method as described in claim 8,wherein said pipeline detecting means is propelled from said floatingvessel means to said first pipeline portion by: pneumatically operatinglatch means to interconnect a source of pressurized air with saidpipeline detecting means; in response to said interconnection of saidsource of pressurized air with said pipeline detecting means, extendingdrive means carried by said pipeline detecting means into drivingengagement with the interior of said pipeline, and operating said drivemeans so as to exert a propellIng force on the interior of said pipelinetending to propel said pipeline detecting means toward said firstpipeline portion; in response to operation of said drive means,propelling said pipeline detecting means from said floating vessel meanssequentially through said second and third pipeline portion to saidfirst pipeline portion; reducing the pressure of said pressurized airand in response to said reduction of pressure disconnecting said sourceof pressurized air from said pipeline detecting means, retracting saiddrive means out of driving engagement with the interior of said pipelinemeans, and discontinuing operation of said drive means; and retrievingsaid source of pressurized air from said pipeline detecting meanssequentially through said second and third pipeline portions to saidfloating vessel means.
 10. A method as described in claim 9, wherein:the step of inducing relative movement between said pipeline detectingmeans and said additional increment of said first pipeline portionresponsively causes detection by said detecting means of a bucklecondition in said additional increment; and wherein a retrieving forceis exerted on said second pipeline portion by said pipeline tensioningmeans to retrieve said additional increment of first pipeline portioncontaining said detected buckle condition on board said floating vesselmeans.
 11. Apparatus for detecting a submerged pipeline condition, saidapparatus comprising: floating vessel means operable to support, atleast in part, a pipeline at an offshore location with a first portionsupported on a submerged surface, a second portion supported on floatingvessel means, and a third portion extending through a body of waterbetween said first and second pipeline portions; pipeline conditiondetecting means positioned within the interior of a submerged portion ofsaid pipeline; said floating vessel means being operable to increase thelength of said pipeline so as to provide an additional submergedpipeline increment; means for inducing relative movement between theadditional submerged pipeline increment and said detecting means, whilesaid detecting means remains within the interior of a submerged portionof pipeline and while said pipeline remains supported, at least in part,by said floating vessel means; said pipeline detecting means beingoperable to detect a condition of said additional submerged pipelineincrement while said pipeline remains supported at least in part, bysaid floating vessel means; said floating vessel means being operable toretrieve said additional submerged pipeline increment by exerting aretrieving force on said second pipeline portion.
 12. Apparatus fordetecting a submerged pipeline condition, said apparatus comprising:floating vessel means operable to support, at least in part, a pipelineat an offshore location with a first portion supported on a submergedsurface, a second portion supported on floating vessel means, and athird portion extending through a body of water between said first andsecond pipeline portions; pipeline condition detecting means positionedwithin the interior of a submerged portion of said pipeline; saidpipeline detecting means being operable to detect a condition of saidsubmerged pipeline portion while said pipeline remains supported atleast in part, by said floating vessel means; pipeline tensioning meanson said floating vessel means operable to engage said second pipelineportion; at least partially submerged buoyant ramp means extending fromand connected with said floating vessel means and supporting, at leastin part, said third pipeline portion; and flexible draft means extendingfrom said pipeline detecting means through the interior of said thirdpipeline portion, over said buoyant ramp means, and through the interiorof said second pipeline portion engaged by said pipeline tensioningmeans On said floating vessel means, said flexible draft means beingoperable to induce relative movement between said first pipeline portionand said pipeline detecting means; and said pipeline tensioning means onsaid floating vessel means being continuously operable to retrieve saidfirst pipeline portion on board said floating vessel means by exerting aretrieving force on said second pipeline portion so as to displace anincrement of said first pipeline portion into said second pipelineportion through movement of said increment upwardly through said body ofwater, over said buoyant ramp means, and onto said floating vesselmeans.
 13. Apparatus as described in claim 11, wherein: said pipelinecondition detecting means comprises means operable, in response torelative movement between said pipeline detecting means and saidpipeline, to detect a buckle condition in said pipeline.
 14. Apparatusfor detecting a dimensional irregularity in an internal cross section ofa submerged pipeline portion, said apparatus comprising: floating vesselmeans operable to support, at least in part, a pipeline at an offshorelocation with a first pipeline portion supported on a submerged surface,a second pipeline portion supported on floating vessel means, and athird pipeline portion extending through a body of water between saidfirst and second pipeline portions; pipeline detecting means; means forpropelling said pipeline detecting means from said floating vessel meanssequentially through said second and third pipeline portions to positionsaid pipeline detecting means within the interior of said first pipelineportion; said pipeline detecting means, when disposed within theinterior of said first pipeline portion, being operable to detect anirregularity in dimension in the cross section of said pipeline inresponse to relative movement between said pipeline detecting means andsaid first pipeline portion; means for increasing the length of saidpipeline from said floating vessel means so as to provide an additionalpipeline increment in said first pipeline portion; means operable fromsaid floating means to induce relative movement between said pipelinedetecting means and said additional increment of said first pipelineportion, with said relative movement being operable to permit saidpipeline detecting means to detect a dimensional irregularity in thecross section of said additional increment of said first pipelineportion; and pipeline retrieving means on said floating means operableto retrieve said additional increment of said first pipeline portion inthe event that said pipeline detecting means should detect a dimensionalirregularity in the cross section of said additional increment of saidfirst pipeline portion.
 15. A method as described in claim 14 including:pipeline tensioning means on said floating vessel means operable toengage said second pipeline portion; at least partially submergedbuoyant ramp means extending from and connected with said floatingvessel means and supporting, at least in part, said third pipelineportion; flexible draft means extending from said pipeline detectingmeans through the interior of said third pipeline portion, over saidbuoyant ramp means, and through the interior of said second pipelineportion engaged by said pipeline tensioning means on said floatingvessel means; said flexible draft means being operable to inducerelative movement between said first pipeline portion and said pipelinedetecting means; and said pipeline tensioning means being continuouslyoperable to retrieve said first pipeline portion on board said floatingvessel means by exerting a retrieving force on said second pipelineportion so as to displace an increment of said first pipeline portioninto said second pipeline portion through movement of said incrementupwardly through said body of water, over said buoyant ramp means, andonto said floating vessel means.
 16. Apparatus as described in claim 15,wherein: said pipeline detecting means comprises means operable, inresponse to relative movement between said pipeline detecting means andsaid additional increment of said first pipeline portion, to detect abuckle condition in said additional increment.
 17. Apparatus fordetecting a dimensional irregularity in an internal cross section of asubmerged pipeline portion, said apparatus comprising: floating vesselmeans operable to support, at least in part, a pipeline at an offshorelocation with a first pipeline portion supported on a submerged portion,a second pipeline portion supported on floating vessel means, and athird pipeline portion extending through a body of water between saidfirst and second pipeline portions; pipeline detecting means; propellingmeans for propelling said pipeline detecting means from said floatingvessel means sequentially through said second and third pipelineportions to position said pipeline detecting means within the interiorof said first pipeline portion; said pipeline detecting means, whendisposed within the interior of said first pipeline portion, beingoperable to detect an irregularity in dimension in the cross section ofsaid pipeline in response to relative movement between said pipelinedetecting means and said first pipeline portion; pipeline sectionalignment means; means operable to connect said pipeline detecting meanswith pipeline section alignment means; said pipeline section alignmentmeans being operable to generally secure in longitudinal alignment afirst additional pipeline section with a terminus of said secondpipeline portion; welding means operable to at least partiallyinterconnect said first additional pipeline section and said secondpipeline portion terminus, with said pipeline section alignment meanssecuring said first additional pipeline section and said second pipelineportion terminus in longitudinal alignment, and remaining connected withsaid pipeline detecting means; means for advancing said first additionalpipeline section on said floating vessel means toward said body ofwater, with said pipeline detecting means remaining connected with saidpipeline section alignment means, and said pipeline section alignmentmeans interconnecting and aligning said first additional pipelinesection and said second pipeline portion terminus; said advancing ofsaid additional pipeline section on said floating vessel means beingoperable to increase the length of said first pipeline portion andprovide an additional pipeline increment in said first pipeline portion;means for positioning a second, additional pipeline section in generallongitudinal alignment with said first additional pipeline section;means for moving said pipeline section alignment means toward saidsecond additional pipeline section, away from said first additionalpipeline section; said movement of said pipeline section alignment meansaway from said first additional pipeline section causing said pipelinedetecting means to move generally toward said additional increment ofsaid first pipeline portion, with this movement being operable to permitsaid pipeline detecting means to detect a dimensional irregularity inthe cross section of said first pipeline portion; said movement of saidpipeline section alignment means away from said first additionalpipeline section being operable to position said pipeline sectionalignment means in position to secure, in mutual longitudinal alignment,a terminus of said first additional pipeline section and a terminus ofsaid second additional pipeline section; and pipeline retrieving meanson said floating means operable to retrieve an increment of said firstpipeline portion in the event that said pipeline detecting means shoulddetect a dimensional irregularity in the cross section of said firstpipeline portion.
 18. Apparatus as descrIbed in claim 17: pipelinetensioning means included in said floating vessel means operable toengage said second pipeline portion; at least partially submergedbuoyant ramp means extending from and connected with said floatingvessel means and supporting, at least in part, said third pipelineportion; flexible draft means connected with said pipeline sectionalignment means and extending from said pipeline detecting means throughthe interior of said third pipeline portion, over said buoyant rampmeans, and through the interior of said second pipeline portion engagedby said pipeline tensioning means on said floating vessel means, saidflexible draft means being operable to induce relative movement betweensaid first pipeline portion and said pipeline detecting means; and saidpipeline tensioning means being continuously operable to retrieve saidfirst pipeline portion on board said floating vessel means by exerting aretrieving force on said second pipeline portion so as to displace anincrement of said first pipeline portion into said second pipelineportion through movement of said increment upwardly through said body ofwater, over said buoyant ramp means, and onto said floating vesselmeans.
 19. Apparatus as described in claim 18, wherein said propellingmeans comprises: a source of pressurized air; pneumatically operatedlatch means operable to interconnect a source of pressurized air withsaid pipeline detecting means; drive means carried by said pipelinedetecting means; positioning means operable to extend and retract saiddrive means; operating means operable in response to saidinterconnection of said source of pressurized air with said pipelinedetecting means, to actuate said positioning means and extend said drivemeans carried by said pipeline detecting means into driving engagementwith the interior of said pipeline, and actuate said drive means so asto exert a propelling force on the interior of said pipeline tending topropel said pipeline detecting means toward said first pipeline portion;said drive means being operable to propel said pipeline detecting meansfrom said floating vessel means sequentially through said second andthird pipeline portion to said first pipeline portion; means forreducing the pressure of said pressurized air and causing, in responseto said reduction of pressure, the disconnecting of said source ofpressurized air from said pipeline detecting means, the actuation ofsaid positioning means to retract said drive means out of drivingengagement with the interior of said pipeline means, and thediscontinuing of actuation of said drive means; and means for retrievingsaid source of pressurized air from said pipeline detecting meanssequentially through said second and third pipeline portions to saidfloating vessel means.
 20. Apparatus as described in claim 19, wherein:said pipeline detecting means comprises means operable, in response torelative movement between said pipeline detecting means and saidadditional increment of said first pipeline portion, to detect a bucklecondition in said additional increment.
 21. A method of eveluating anoffshore pipeline laying operation, said method comprising: conductingan offshore pipeline laying operation; during said offshore pipelinelaying operation, supporting a portion of said pipeline on floatingvessel means, with the floating vessel means being operable to effectretrieval of previously laid pipeline increment means; and prior to thetermination of said offshore pipeline laying operation, and while aportion of said pipeline is supported on said floating vessel means andwhile said floating vessel means remains operable to effect retrieval ofpreviously laid pipeline increment means, detecting a condition of asubmerged portion of said pipeline; the step of detecting beingperformed by scanning a submerged portion of the pipeline with pipelinecondition dEtecting means operable to detect a pipeline condition whichis detectable prior to the termination of the laying of said pipelineand is operable to remain in said submerged portion of the pipelineafter the termination of the pipeline laying operation.
 22. A methodaccording to claim 21 wherein: the steps of conducting the offshorepipeline laying operation and supporting a portion of the pipeline onfloating vessel means comprise laying the pipeline from the floatingvessel means and onto a submerged surface with the pipeline profileincluding a downwardly concave pipeline portion extending to a pipelineportion on the submerged surface; and wherein the step of detectingcomprises detecting a pipeline condition at a pipeline location beyondthe downwardly concave pipeline portion.